1. Field of the Invention
The present invention relates to weather strips for motor vehicles, and, more particularly, to a structure for attachment of weather strips to openings of vehicle bodies, which are closed and opened by closing members such as doors.
2. Description of Related Art
Along door openings formed in a side body of a motor vehicle, for example, as shown in FIG. 1, weather strips W are installed along a roof side rail 10 and a center pillar 12 to provide seals around door window panes 14. These weather strips W are attached to vehicle bodies with retainers (Japanese Utility Model application laid-open No. Hei 1-68218).
More specifically, as shown in FIG. 2, which is a cross-sectional view taken along the line 2--2 of FIG. 1, a retainer 16 is secured to a bottom wall of the roof side of rail 10, which defines a door opening of a vehicle body, and a tubular weather strip W1 is fitted in the retainer 16. Furthermore, as shown in FIG. 3, which is a cross-sectional view taken along the line 3--3 of FIG. 1, retainers 17 and 18 are respectively installed along front and rear surfaces of an outer panel of the center pillar 12. A weather strip W2 is composed of weather strips W2A and W2B on which front and rear door window panes 14 respectively abut upon closing of a vehicle door. These weather strips W2A and W2B are respectively fitted in the retainers 17 and 18. In FIGS. 2 and 3, reference numeral 20 denotes a roof side molding, 21, 22 and 23 denote opening trims. The retainers are secured to vehicle bodies with screws or the like, and seal members are interposed between the retainers and the vehicle bodies to provide a good seal therebetween.
Recently, the adhesive properties of double-sided adhesive tapes have been improved. Further, it has been necessary to reduce the manufacturing costs of vehicles. Under the above circumstances, the double-sided adhesive tapes have been used frequently to attach the weather strips in place of the retainers. (Japanese Utility Model application laid-open No. Hei 1-112110).
Namely, in the case of weather strips for attachment around door openings, for example, as shown in FIG. 4, a base portion 28 of a weather strip W3 is bonded to a bottom wall 11 of a roof side rail with a band-shaped double-sided adhesive tape 24 of a width nearly equal to or slightly less than that of the base portion 28. In the drawing, reference numeral 25 denotes a drip moulding, and numeral 26 denotes an opening trim.
The double-sided adhesive tape (hereinafter merely called "adhesive tape") generally has a thickness of about 10 mm. If the adhesive tape is too thin, the adhesive tape cannot smoothly cover the step-like surface of the bottom wall 11, which is formed around joints therein. This causes the adhesive tape not to closely contact the bottom wall 11, thereby forming spaces between the adhesive tape and the vehicle body. This degrades the adhesive and sealing properties of the weather strip against the vehicle body.
In order to improve sealing performance, it is preferable to use thicker adhesive tapes. However, when thick and wide adhesive tapes are curved in conformity to corner portions of vehicle bodies around door openings, they are likely to be undesirably buckled or deformed due to the difference in external diameter and internal diameter of curved adhesive tapes. This results in the thick and wide adhesive tapes not being bonded securely to the vehicle bodies and they may peel-off therefrom. As a result, the sealing properties between the weather strips and the vehicle bodies is degraded. Additionally, the production costs of the thick adhesive tapes are expensive.
In order to solve the above-described problems, soft adhesive tapes may be used. The adhesive tapes are generally composed of a band-shaped foamed portion and adhesive layers provided on both sides of the band-shaped foamed portion. These adhesive tapes can be made soft by varying the stiffness of the foamed portion. The resulting soft adhesive tapes can deform in conformity to the step-like surface of the vehicle bodies to which the weather strips are attached. When a door is closed, the door window pane presses the weather strips attached to the vehicle body to generate such forces as to pull and distort the weather strips. If such forces are repeatedly applied, the soft foamed portions of the adhesive tapes are likely to be damaged.
In the case that long weather strips bonded to a roof side rail and a pillar, which define a door opening, the adhesive tapes are likely to deviate from the predetermined attaching positions or to be distorted. This causes lowering of the sealing properties thereof. Accordingly, in attaching weather strips with adhesive tapes, skill and close attention have been conventionally required, so that good work efficiency has not been conventionally achieved.